Chair iron and mounting plate therefor

ABSTRACT

A chair iron having a one piece mounting plate with rigid downwardly extending ears which rigidly mount a spindle bracket and pivotably mount a back rest yoke. The integrally formed mounting plate reduces material costs, weight of the chair iron, and manufacturing costs.

lmited States Patent [1 1 De Graaf [54] CHAIR IRON AND MOUNTING PLATE THEREFOR [75] Inventor: Clare J. De Graal, Grand Rapids,

Mich.

[73] Assignee: Gordon Manufacturing Co., Grand Rapids, Mich;

[22] Filed: March 8, 1971 211 App1.No.:121,789

[52] U.S. Cl. ..297/306, 297/361 [51] Int. Cl ..A47c U023 [58] Field oi Search ..297/306, 300-305;

[56] References Cited UNITED STATES PATENTS 1,399,465 12/1921 Collier ..248/l88.7 1,416,693 5/1922 Dawson ..248/188.7

[ 51 Jan. 23, 1973 4/1969 Doemer ..297/349 X 3,453,024 7/ 1969 Williams ..297/304 2,140,058 12/1938 Sheldrick ..297/305 3,042,448 7/1962 Hamilton ..297/30l 1,767,166 6/1930 Bolens ..248/38l 2,557,736 6/1951 Fox ..297/305 2,211,090 8/1940 Bolens ..297/305 1,368,469 2/1921 Atwood. ..297/304 755,560 3/1904 Bolens ..248/380 Primary ExaminerFrancis K. Zugel Attorney-John E. McGarry [57] ABSTRACT A chair iron having a one piece mounting plate with rigid downwardly extending ears which rigidly mount a spindle bracket and pivotably mount a back rest yoke. The integrally formed mounting plate reduces material costs, weight of the chair iron, and manufacturing costs.

9 Claims, 4 Drawing Figures CHAIR IRON AND MOUNTING PLATE THEREFOR BACKGROUND OF THE INVENTION This invention relates to chair irons and a mounting plate therefor.

Swivel chairs having a tilting backrest are well known and are commercially used for secretarial chairs. Such chairs commonly have been supported by a wheeled base and a spindle which is rotatably mounted on the base. The chair is rigidlyconnected to the spindle by means of a chair iron which also controls the tilting function of the back rest. Normally, such chair irons contain mechanisms for adjusting the angular relationship between the seat and backrest and means for adjusting the tension on the backrest as it tilts with respect to the seat.

The chair iron must provide a broad based support for securing the chair iron to the underside of the chair. Conventionally, a pair of angle irons with diverging ends have been employed for this purpose. The spindle mounting mechanism and the back rest mechanism are secured to the angle irons. These conventional chair irons normally require a pair of U-brackets, inverted with respect to each other, to secure the spindle to the angleirons. These chair irons further require a second pair of brackets to mount the backrest and a backrest biasing means to the angle irons.

The resulting chair irons require expensive hand operations to assemble the many parts. The cost of the chair iron is also directly related to the number of parts and the amount of material which is required to form these parts. Still further, the appearance of the conven tional chair iron is bulky and detracts from the appearance of the more modern chairs. Many modifications of this basic design have been made without eliminating the many parts, the hand labor, and bulky appearance. Such a modification is shown in U.S. Pat. No. D2l2,689.

OBJECTS By various aspects of this invention one or more of the following, or other, objects can be obtained.

It is an object of this invention to provide a chair iron for a chair with a tilting backrest wherein the chair iron has fewer parts and is more easily assembled.

It is a further object of this invention to provide a chair iron for a chair with a tilting backrest wherein the chair iron has fewer parts and is more easily and inexpensively manufactured.

It is another object of this invention to provide a chair iron for a chair with a tilting backrest wherein the chair iron is of simple and light weight construction.

It is yet another object of this invention to provide a chair iron for a chair with a tilting backrest wherein the chair iron is slimmer and less bulky in appearance.

' BRIEF STATEMENT OF THE INVENTION According to the invention, a chair iron has a one piece integrally formed mounting plate with a base portion for securing the chair iron to the underneath surface of a chair and a pair of downwardly extending ears integrally formed with the base portion by bending downwardly the central portions of opposite sides of a rectangular'plate leaving indentations in the opposite sides of the rectangular plate. The ears have side portions integrally formed therewith and with the base portion, the side portions extending angularly of the ears outwardly to the outer edges of the base portion. In this manner, the ears are braced and very rigid with respect to the base portion.

The base portion of the mounting plate has a means for engaging the top of a spindle. A bracket is rigidly secured to the ears beneath the spindle engaging means and also has a spindle engaging means for rigidly securing the spindle to the chair iron. A yoke is pivotably mounted to one end portion of the ears and means bias the yoke upwardly with respect to the mounting plate. A backrest bracket is mounted on the chair portion of the yoke for supporting a backrest for the chair.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a bottom of a chair incorporating a chair iron according to the invention;

FIG. 2 is a side elevational view in section of the chair iron illustrated in FIG. .1, as seenalong lines 22 of FIG. 3;

FIG. 3 is a bottom view of the chair iron taken along lines 3--3 of FIG. 2; and

FIG. 4 is a partial side view of the chair iron illustrating the manner in which adjustment is made between the backrest and the chair iron.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and to FIGS. 1 through 3 in particular, there is shown a chair having a seat support 12 mounting a chair iron 14. A spindle 16 is secured beneath the chair iron 14 and is mounted on a conventional base 18.

The chair iron 14 comprises a mounting plate 20, a U-bracket 22, a yoke 24 and a backrest mounting plate 32. A carriage bolt 26 is secured at its upper end to the mounting plate 20 and extends through the yoke 24. A handle 28 threadably engages the lower end of the carriage bolts 26 and retains a helical spring 30 between the bottom of the yoke 24 and the handle 28. The back mounting plate is pivotably secured 'to the yoke 24 through rivets 34.

As seen in FIG. 3, the mounting plate 20 is an integrally formed rectangular plate having a generally planar base portion 37 with wide front and rear portions. Wood screws 36 extend through holes in the plate at front and rear portions to secure the mounting plate 20 the the bottom of the chair seat support 12. An opening 38 is provided in the front portion of the mounting plate, said opening 38 being defined by a downwardly extending lip 40.

In a central portion of the mounting plate 20, a depression 42 having a hole 44 is formed. The top of the spindle 16 extends through the hole and is secured therein by expanding the head of the spindle at 60.

Ears 46 are bent downwardly from the sides of a central portion of the mounting plate 20 leaving wide indentations as seen from FIG. 3. These ears 46 have sides 48 increasing in height from the outer edges of the mounting plate to the central portion of the cars.

A depression 50 having a square hole 52 is formed at a rear portion of the mounting plate 20 for reception of the head of the carriage bolt 26.

The U-bracket 22 has flanges 54 which extend upwardly within the cars 46. Rivets 56 extend through the cars 46 and through the flanges 54 to rigidly secure the U-bracket to the mounting plate 20. A hole 58 is provided in the bottom of the U-bracket to receive the upper portion of the spindle 16.

The yoke 24 has upturned side flanges 62 which at their forward end extend within ears 46. Bosses 64 are formed in the upper forward most corners of the yoke 24. Rivets 66 extend through the side flanges 62 at the bosses 64 and through ears 46 to pivotably secure the yoke to the mounting plate 20. Bosses 68 are formed at upper rear portions of the yoke 24 for reception of rivets 34. A concave downward indentation '70 having a large opening 72 at the upper portion thereof is formed in the bottom of yoke 24. The upper end of the helical spring 30 is received within the indentation 70. The carriage bolt 26 passes through the hole 72.

The back mounting plate 32 has a pair of side flanges 76 through which rivets 34 pass to pivotably mount the plate 32 on the yoke 24. A vertical slot 78 in the back of the mounting plate 32 is provided for mounting a backrest on the plate 32.

Ordinarily the back mounting plate 32 is maintained rigid with respect to the yoke 24 by an adjustable device which is illustrated in FIG. 4. The device comprises a socket 80 pivotably mounted in one side flange 76 of the back mounting plate 32, a socket 82 pivotably mounted in a side flange 62 of yoke 24, and a rod 84 having oppositely threaded ends 86 and 88. The sockets 80 and 82 threadably engaged the threaded ends 86 and 88 respectively of rod 84. A handle 90 is provided for adjusting the relationship between the backrest mounting plate 32 and the yoke 24.

In operation, it can be seen that the spindle is rigidly mounted on the mounting plate through U-bracket 22. The yoke 24 which mounts the backrest is pivotably mounted on rivets 66 with respect to the mounting plate 20 against the tension of spring 30. Rotation of handle 28 adjusts the tension of spring 30. The normal relationship between the backrest and the seat can be altered by rotation of handle 90 which adjusts the relationship between the back mounting plate 32 and the yoke 24.

The mounting plate 20 is advantageously made from a rectangular sheet of metal, such as steel, by bending downwardly the opposite side edges of the plate leaving wide indentations at the sides of the sheet. Such bending can be done in a stamping operation in which progressive dies are used. The sides 48 are formed integrally with the operation and serve to brace the ears 56 with respect to the base of the mounting plate. The ears are thus strongly and rigidly secured against lateral force between the ears and the base of the mounting plate. The depression 50 and 42 and the lip 40 can also be formed during the stamping operation. The mounting plate is wide at the front and rear portions to provide adequate support for the chair and yet narrow at the central portion to strongly support the spindle with a minimum ofmaterial.

The chair iron of the inventionis less bulky-in appearance than conventional chair irons and is thus more readily adaptable to more modern chairs. It is apparent that the easily manufactured mounting plate reduces the number of parts which need be assembled. Manufacturing costs are thereby reduced. Further, the

mounting plate is light in weight, yet very rigid and functional. It is thus possible to reduce the overall weight of the chair iron as compared with previous chair irons.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, drawings and appended claims without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A chair iron comprising:

a one piece integrally formed mounting plate having a base portion for securing said chair iron to the underneath surface of a chair, a pair of downwardly extending parallel ears integrally formed with said base by bending downwardly the central portions of opposite sides of a rectangular plate, leaving indentations in said opposite sides of said rectangular plate, said ears having side portions integrally formed therewith and with said base portion, said side portions joining said base portion and extending angularly of said ears outwardly to the outer edges of said base portion, thereby bracing said ears with respect to said base portion, and means on said base portion between said ears for securely retaining a top portion of a spindle against lateral movement with respect to said mounting plate;

a bracket rigidly secured to said ears beneath said spindle retaining means for rigidly securing said spindle to said chair iron;

a yoke pivotably mounted to one end portion of said ears;

means biasing said yoke upwardly with respect to said mounting plate; and

means on a back portion of said yoke for supporting a backrest for said chair.

2. A chair iron according to claim 1 wherein said biasing means comprises a bolt pivotably mounted at one end to a rear portion of said mounting plate and a spring biased between the other end of said bolt and said yoke.

3. A chair iron according to claim 2 wherein said base portion has a depression receiving the head of said biasing means bolt.

4. A chair iron according to claim 1 and further comprising means to adjust the angular relationship between said yoke and said backrest supporting means.

5. A chair iron according to claim 1 and further comprising a large opening in said base member at a front portion thereof, said opening being defined by a downwardly extending lip, thereby adding rigidity to said base member.

6. A chair iron according to claim 1 wherein said spindle retaining means on said base portion comprises a depression formed downwardly of the plane of said base member, and an aperture in said depression for receiving said top portion of said spindle.

7. A chair iron according to claim 1 wherein said side portions of said ears decrease in height from said ears to said edges of said base portion.

8. A chair having a seat, a backrest, a base, a spindle mounted on said base, and a chair iron according to claim I mounted on said spindle;

means securing said base portion of said chair iron to a bottom surface of said chair seat; and

means securing said backrest to said backrest bracket supporting means.

9. A chair iron comprising:

an integral rigid mounting plate having a base portion for securing said chair iron to the underneath surface of a chair, a pair of downwardly extending parallel ears integrally formed with said base, said ears having side portions integral therewith and with said base portion, said side portions joining said base portions and extending angularly of said ears outwardly to the outer edges of said base portion, thereby bracing said ears with respect to said base portion, and means on said base portion 

1. A chair iron comprising: a one piece integrally formed mounting plate having a base portion for securing said chair iron to the underneath surface of a chair, a pair of downwardly extending parallel ears integrally formed with said base by bending downwardly the central portions of opposite sides of a rectangular plate, leaving indentations in said opposite sides of said rectangular plate, said ears having side portions integrally formed therewith and with said base portion, said side portions joining said base portion and extending angularly of said ears outwardly to the outer edges of said base portion, thereby bracing said ears with respect to said base portion, and means on said base portion between said ears for securely retaining a top portion of a spindLe against lateral movement with respect to said mounting plate; a bracket rigidly secured to said ears beneath said spindle retaining means for rigidly securing said spindle to said chair iron; a yoke pivotably mounted to one end portion of said ears; means biasing said yoke upwardly with respect to said mounting plate; and means on a back portion of said yoke for supporting a backrest for said chair.
 2. A chair iron according to claim 1 wherein said biasing means comprises a bolt pivotably mounted at one end to a rear portion of said mounting plate and a spring biased between the other end of said bolt and said yoke.
 3. A chair iron according to claim 2 wherein said base portion has a depression receiving the head of said biasing means bolt.
 4. A chair iron according to claim 1 and further comprising means to adjust the angular relationship between said yoke and said backrest supporting means.
 5. A chair iron according to claim 1 and further comprising a large opening in said base member at a front portion thereof, said opening being defined by a downwardly extending lip, thereby adding rigidity to said base member.
 6. A chair iron according to claim 1 wherein said spindle retaining means on said base portion comprises a depression formed downwardly of the plane of said base member, and an aperture in said depression for receiving said top portion of said spindle.
 7. A chair iron according to claim 1 wherein said side portions of said ears decrease in height from said ears to said edges of said base portion.
 8. A chair having a seat, a backrest, a base, a spindle mounted on said base, and a chair iron according to claim 1 mounted on said spindle; means securing said base portion of said chair iron to a bottom surface of said chair seat; and means securing said backrest to said backrest bracket supporting means.
 9. A chair iron comprising: an integral rigid mounting plate having a base portion for securing said chair iron to the underneath surface of a chair, a pair of downwardly extending parallel ears integrally formed with said base, said ears having side portions integral therewith and with said base portion, said side portions joining said base portions and extending angularly of said ears outwardly to the outer edges of said base portion, thereby bracing said ears with respect to said base portion, and means on said base portion between said ears for securely retaining a top portion of a spindle against lateral movement with respect to said mounting plate; a bracket rigidly secured to said ears beneath said spindle retaining means on said base portion, said bracket also having a spindle retaining means for rigidly securing said spindle to said chair iron; a yoke pivotably mounted to one end portion of said ears; means biasing said yoke upwardly with respect to said mounting plate; and means on a back portion of said yoke for supporting a backrest for said chair. 